Fix fast inverse sqrt (fixes #3199) (#3228)

Co-authored-by: Andrii Siriak <siryaka@gmail.com>

src/test/java/com/thealgorithms/maths/FastInverseSqrtTests.java

@@ -0,0 +1,56 @@
+package com.thealgorithms.maths;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+
+
+public class FastInverseSqrtTests {
+    @Test
+	void testForOneElement() 
+	{
+		assertFalse(FastInverseSqrt.inverseSqrt(1332));
+        // calls for the 2nd inverse method
+    }
+	@Test
+	void testForsecond() 
+	{
+		assertFalse(FastInverseSqrt.inverseSqrt(1332f));
+        // calls for the 1st inverse method
+	}
+
+	@Test
+	void testForThird() 
+	{
+		assertFalse(FastInverseSqrt.inverseSqrt(1));
+	}
+    
+	@Test
+	void testForFourth() 
+	{
+		assertFalse(FastInverseSqrt.inverseSqrt(1f));
+	}
+
+	@Test
+	void testForFifth() 
+	{
+		assertFalse(FastInverseSqrt.inverseSqrt(4522));
+	}
+    
+	@Test
+	void testForSixth() 
+	{
+		assertFalse(FastInverseSqrt.inverseSqrt(4522f));
+	}
+
+	@Test
+	void testForSeventh() 
+	{
+		assertFalse(FastInverseSqrt.inverseSqrt(21));
+    }
+
+	@Test
+	void testForEighth() 
+	{
+		assertFalse(FastInverseSqrt.inverseSqrt(21f));
+	}
+}